High-performance hydrolysis of cellulose using mixed cellulase species and ultrasonication pretreatment

Imai, Masanao; Ikari, Kohei; Suzuki, Isao

doi:10.1016/s1369-703x(03)00141-4

Cited by 103 publications

(58 citation statements)

References 7 publications

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“…A plot of this using the generated experimental data in this work is shown in Figure 8 from which the kinetic parameters (r max and k m ) were estimated as 1.5288*10 -4 g/l s and 33.7 g/l, respectively. The maximum reaction rate r max (1.5288*10 -4 g/l s) was found comparable to the values 0.1910 -1.77666*10 -4 g/l s reported by Imai et al (2004) for hydrolysis of a soluble cellulose (CMC) using the synergetic effects of combined cellulases from Trichoderma viride and A. niger. It is believed that this comparative value despite the use of real substrate (insoluble cellulose) in this work can be attributed to the continuous excretion of enzymes into the system by the cells, which was able to mask effectively the often reported glucose inhibitory effect on cellulase from A. niger.…”

Section: Development Of Kinetic Modelsupporting

confidence: 83%

The kinetics of glucose production from rice straw by Aspergillus niger

Aderemi¹,

Abu²,

Highina³

2008

Afr. J. Biotechnol.

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In this investigation, glucose was produced from rice straw using cells of Aspergillus niger, isolated from maize grain. Glucose yield was found to increase from 43 to 87% as the rice straw particle size decreased from 425 to 75 µm, while the optimal temperature and pH were found within the range of 45 -50°C and 4.5 -5 respectively. The concentration and rate of glucose production was observed to depend on pretreatment of rice straw, substrate concentration and cell loading. A kinetic model rate expression has been developed for such a process based on the Michaelis -Mentens and LineweaverBurk approach. Comparison between the experimental data and those predicted from the rate model indicate good agreement with a mean absolute deviation of about 0.2.

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Section: Development Of Kinetic Modelsupporting

confidence: 83%

The kinetics of glucose production from rice straw by Aspergillus niger

Aderemi¹,

Abu²,

Highina³

2008

Afr. J. Biotechnol.

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“…Digestibility of lignocellulosic materials can be enhanced by the application of high energy radiation methods, such as microwave heating [173][174][175] and ultrasound [176,177]. The treatments can cause hydrolysis of hemicellulose, and partial depolymerization of lignin, the increase of specific surface area, decrease of the degrees of polymerization and crystallinity of cellulose.…”

Section: Combination With High Energy Radiation Treatmentmentioning

confidence: 99%

Lignocelluloses Feedstock Biorefinery as Petrorefinery Substitutes

Cheng¹,

Wang²

2013

Biomass Now - Sustainable Growth and Use

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Lignocelluloses Feedstock Biorefinery as Petrorefinery Substitutes 349The LCF Biorefinery is a promising alternative due to the abundance and variety of available raw materials and the good position of the conversion products on the market [14]. Its profitability is also dependent on the technology employed to alter the structure of lignocellulosic biomass in order to produce high value co-products from its three main fractions i.e. cellulose, hemicellulose, and lignin [15].Currently the main feedstock for biorefineries is still based on starch. The practiced technologies in fuel ethanol industry are primarily based on the fermentation of sugars derived from starch and sugar crops, which are quite mature with little possibility of process improvements. However, using starch and sugar crops to produce ethanol also has been questioned since it draws its feedstock from a food stream. Lignocellulosic biomass is a more promising renewable resource as it is available in large quantities and does not compete with food or feed. Lignocellulosic biomass is a renewable resource that stores energy from sunlight in its chemical bonds, with great potentials for the production of affordable fuel ethanol [16,17]. Its main obstacle for a major breakthrough is the high production costs for bioenergy products.On the other hand, lignocellulosic biomass-derived products can significantly reduce green house gas emissions, compared to fossil-based products. Also, many common petrochemicals could be obtained with lower green house gas emissions from bio-based feedstocks. The maturity and economics of the conversion processes and logistics is a major challenge for lignocellulosic biomass [18].

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“…O formulado ideal pode ser obtido pelo cocultivo de linhagens superprodutoras dos principais tipos de celulases; 95 pela produção em separado das celulases e posterior mistura dos extratos, em proporções pré-otimizadas; [92][93][94][96][97][98][99][100] ou ainda pela incorporação controlada de genes de celulases em organismos hospedeiros, de forma que a célula modificada já excrete as enzimas em proporções ideais. 61 No âmbito da produção de etanol a partir de materiais lignocelulósicos, as celulases são insumos que impactam significativamente o processo, podendo representar até 18% do custo operacional de uma planta.…”

Section: Tendências Futuras Para a Produção E Aplicação De Celulasesunclassified

Produção, propriedades e aplicação de celulases na hidrólise de resíduos agroindustriais

Castro¹,

Pereira²

2010

Quím. Nova

107

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Recebido em 13/5/09; aceito em 24/6/09; publicado na web em 25/11/09 PRODUCTION, PROPERTIES AND APPLICATION OF CELLULASES IN THE HYDROLYSIS OF AGROINDUSTRIAL RESIDUES. Cellulases have been intensively studied in the past few years, due to the interests in biofuels production from lignocellulosic materials, since they permit maintaining mild conditions during the conversion process. These enzymes can be produced by a broad variety of naturally occurring microorganisms, such as from genera Aspergillus, Trichoderma, Penicillium and Humicola. Targeting the increasing of expression levels, molecular biology tools have been used for heterologous genes insertion in host cells, e. g., Pichia pastoris and Escherichia coli. Enzymes from fungal cellulolytic complex usually act best at pH between 4 and 5 under temperatures from 40 to 60 °C and can be used for either sequential (SHF) or simultaneous (SSF) hydrolysis together alcoholic fermentation. In this review, the main raw materials for production of cellulases are identified, as well as the state of art of enzymes' properties, production and main applications.Keywords: cellulases; agroindustrial residues; lignocellulose. INTRODUÇÃOCelulases são enzimas que constituem um complexo capaz de atuar sobre materiais celulósicos, promovendo sua hidrólise. Estas enzimas são biocatalisadores altamente específicos que atuam em sinergia para a liberação de açúcares, dos quais glicose é o que desperta maior interesse industrial, devido à possibilidade de sua conversão em etanol. 1,2Estas enzimas começaram a ser estudadas durante a Segunda Guerra Mundial. A deterioração de fardas, barracas, bolsas e demais objetos dos acampamentos, fabricados de algodão, chamou a atenção de soldados das forças armadas norte-americanas, instalados nas ilhas Solomon, no Pacífico Sul. Algumas organizações, como a Quartermaster Corps, juntamente com as forças armadas, montaram laboratórios em busca de explicações e soluções imediatas para esse problema, que incluíam a detecção de organismos agentes das deteriorações, seus mecanismos de ação e métodos de controle. O grupo de trabalho, constituído por oito pesquisadores e liderado pelo Dr. Elwyn T. Reese, passou a conduzir seus experimentos no laboratório das forças armadas, em Natick, Massachusets, Estados Unidos. Como resultado das pesquisas, uma linhagem, codificada como QM6a, de um fungo filamentoso, identificado posteriormente como Trichoderma viride, foi isolada e a esta foi atribuída a característica de excretar enzimas capazes de degradar celulose. Até 1953, Dr. Reese e seu grupo de trabalho já haviam determinado que enzimas naturais, nomeadas celulases, constituem complexos de diversas moléculas com distintas habilidades na degradação do substrato. Em 1956, Dr. Reese aliou seus conhecimentos aos da Dra. Mary Mandels, que, em conjunto, passaram a trabalhar no laboratório em Natick. A partir de então, o foco das pesquisas deixou de ser a prevenção da hidrólise da celulose e passou a ser o melhoramento da produção das enzimas responsáveis por esse fe...

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High-performance hydrolysis of cellulose using mixed cellulase species and ultrasonication pretreatment

Cited by 103 publications

References 7 publications

The kinetics of glucose production from rice straw by Aspergillus niger

The kinetics of glucose production from rice straw by Aspergillus niger

Lignocelluloses Feedstock Biorefinery as Petrorefinery Substitutes

Produção, propriedades e aplicação de celulases na hidrólise de resíduos agroindustriais

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